In continuous casting installations for casting metal strands, rotatably mounted rollers are used, the purpose of which is to guide the metal strand along a predetermined path after leaving the mold and to cool it and possibly support it. In that case the rollers are supported externally by way of journals in a bearing block by means of bearings and are cooled in a closed circuit by a feed of a coolant (in particular water) under pressure into the interior of the roller to dissipate the heat, which can be implemented for example by way of the water circuit by way of an axial roller bore passed through the journals.
Depending on the respective casting format and position, support and/or guidance for the metal strand can be effected on all sides, from opposite sides thereof or only from the underside of the strand. Accordingly the rollers are used in different arrangements such as roller rings, displaced double rollers, longitudinal rollers supported in a multiple array or in the form of simple rollers.
The rollers and in particular the peripheral roller casings and the bearings are exposed in operation to an extreme thermal loading by virtue of direct contact with the glowing metal strand and in particular due to radiant heat. That applies in particular to rollers in the web region when dealing with beam blank profiles. Added to that is the aggressive environment, caused by water contaminated with casting powder residues and by water vapour, scale and so forth.
In many cases close spacings are required between the adjacent rollers and consequently the rollers need to be of small diameters in order to efficiently support the casting strand, and that additionally increases the loading on the rollers.
Such close spacings in relation to adjacent strands and other components of the casting installation such as cooling elements or electromagnetic agitator apparatuses require the roller guides to be of as compact a structure as possible. Nonetheless the rollers used and the roller arrangement thereof must enjoy a high level of reliability and afford a long service life and also allow easy maintenance.
The solutions known in the state of the art with bearing blocks at both ends of the generally water-cooled roller body and a separate rotary feed connecting assembly mounted to the bearing block often only inadequately meet the above-mentioned demands.
Examples of such roller arrangements which are known in the state of the art are known from DE 19752336 C1 and EP 857258 A1. In such constructions in particular cooling of the bearing regions is often inadequate.